Internet traffic is experiencing a rapid growth driven by massive video streaming, cloud computing and the Internet of Things. Green networking is more important than ever to keep energy consumption under control while still guaranteeing good service quality. Packet switching is the standard practice in high speed Internet, enabled by routers and switches that perform electronic packet store-and-forward at every intermediate node. In a typical router, up to 60 percent of its energy is used for packet forwarding. Circuit switching, on the other hand, does not require per-packet store-and-forward and can potentially be more energy efficient. Current practice places optical circuits on a fixed grid of optical frequences. This fixed grid may waste valuable optical spectrum if an optical circuit is carrying less than the maximum capacity. Thus both the research community and industry are investigating grid-less approaches. In particular, Digital Subcarrier Multiplexing (DSCM)is a circuit-oriented approach with high spectral efficiency and robustness against signal quality corruption and which enables flexible spectrum and grid-less transmission in optical networks.
This project leverages DSCM to extend the circuit-oriented practice from the optical network core all the way to the network periphery (including metro, access and campus segments) ultimately offering dedicated broadband DSCM circuits to end-users. DSCM traffic bypasses both Ethernet switches and Internet Protocol routers, and eliminates the energy consumption associated with their packet store-and-forward requirements. The project also explores a Hybrid-DSCM-Ethernet network architecture in which DSCM circuits and Ethernet frames coexist in the access/campus networks. The transmission and network cross-layer nature of this research effort promotes partnerships among different institutions and research areas, and provides graduate and undergraduate students the opportunity to do research solving real-world scientific problems.
